2010 silverado vibration

[wvetre]

My 2010 Silverado 4x4 5.3 6 speed 3.08 rear end is violently vibrating ONLY when I tow a trailer around 65-75 mph. It comes and goes for a second at a time. the weird thing is it randomly does it for 20 minutes and then stops... some days it does it and others it doesn't. the transfer case has been rebuilt because it had burnt fluid and was doing this before towing and not towing... now it only does it during towing.... any ideas? the floorboard and steering wheel is what is vibrating the most.

[Doug_Scott]

Have you tried changing to a gear that does lock the torque convertor? When the convertor is locked up, any miss in the engine will be amplified. Also, your truck in high gear with the 3.08 gears running 65mph must have an engine speed under 1500rpm doesn't it?

I would try downshifting to 4th when it is happening and see what happens. What grade fuel have you been running in the truck? And have you checked for stored codes in the computer? Don't assume there were none when the dealer checked it last time.

[wvetre]

it does it in every gear 3-6 (I don't dare go any lower) and the higher the rpm it seems to say the same....but worse with speed. i run 87 octane and yes at 65 it runs at 1400rpm. I should also add its running in v8 nit v4 when this is occuring

[Doug_Scott]

If rebuilding the transfer case made a difference, that would lead me towards the transfer case, and the parts that were physically touched for the removal in installation of transfer case.

[wvetre]

even though it was doing this before the transfer case was ever touched?

[Doug_Scott]

even though it was doing this before the transfer case was ever touched?

 

He has said it was worse before they did the transfer case. The vibration was there both towing and not towing. After the repair, it changed to be only when towing.